Which notion of implication is the right one? From logical considerations to a didactic perspective

Implication is at the very heart of mathematical reasoning. As many authors have shown, pupils and students experience serious difficulties in using it in a suitable manner. In this paper, we support the thesis that these difficulties are closely related with the complexity of this notion. In order to study this complexity,we refer to Tarski's semantic truth theory,which contributes to clarifying the different aspects of implication: propositional connective, logically valid conditional, generalized conditional,inference rules. We will show that for this purpose, it is necessary to extend the classical definition of implication as a relation between propositions to a relation between open sentences with at least one free variable. This permits to become aware of the fact that, in some cases, the truth-value of a given mathematical statement is not constrained by the situation, contrary to the common standpoint that, in mathematics, a statement is either true or false. In the present paper, the didactic relevance of this theoretical stance will be illustrated by an analysis of two problematic situations and the presentation of some experimental results from our research on first-year university students' understanding of implication. This revised version was published online in August 2006 with corrections to the Cover Date.     

再论公车上书

百年之后,回顾康有为他们当初在清末政坛中的政改方案和上书活动,后人无疑可以做到更冷静、更持中和更客观.鄙薄康梁的人认为:荣禄老成,项城务实.问题是老城谋国的荣禄、精明强干的袁世凯也没有支撑住大局,也没有稳住一个合法性消失的王朝和适应性不够的传统社会.<上清帝第二书>中包括设议院(武英殿)的所有的内容,无论是对洋务派官员、还是对实权派官员,都没有智力、观念上的障碍.在官场中,方案、策略的提出者必须讲究身份和资历,资历不够、派系不对的人提出的方案再高明也很难取得官场主流中人的呼应,更何谈实践.既得利益集团积重难返是清末改良搁浅问题的关键.     

会计信息化下的XBRL与会计课程整合研究

在当今日新月异的信息时代,高校人才培养的首要目标是培养既能精通会计、财务等经济管理知识,又能掌握国际通用信息技术相关知识和技能的复合型人才。XBRL（ExtensibleBusinessReportingLanguage,可扩展商业报告语言）是当前国际上最新的在互联网环境下披露企业信息的标准化财务报告电子语言,在将相互关联的元数据与会计信息自动转换方面,XBRL具有重要作用。世界大多数发达国家已经在各种多样化的信息价值链中自愿或强制地使用XBRL,提升了会计信息质量。XBRL对高校本科会计课程及教育模式具有重要影响,基于布卢母教育目标分类学理论,可以将XBRL与高校本科会计学专业课程进行整合。     

初探《工业分析》理实一体化的教学方法

化工分析工是高职化工类专业学生就业的重要方向,将学生培养成为一名合格的化工分析工是我们教改的最终目标。＂理实一体化＂的教学方法以企业案例作为引领项目把学生引入教学内容,达到＂做中教、做中学,寓教、学、做于一体＂,让学生在完成工作任务的过程中学习相关知识。     

使命和责任——对新闻传播学科通识教育的认识和实践

通识教育是对已经积重很深的应试教育的反拨,湖南师范大学新闻与传播学院对此的认识和实践表现为:"天下"成为学院教育教学的一个核心理念,"做通晓天下的新闻传播人才"成为学院教育教学的一个总纲;"读书为本,不同流俗",成为学院施教的基本导向;打造"书山文化",形成"境教"的合力,成为学院环境建设和氛围建设的基本举措.这种认识...     

Olivine-norite rock detected by the lunar rover Yutu-2 likely crystallized from the SPA-impact melt pool

Chang’E-4 landed in the South Pole-Aitken (SPA) basin, providing a unique chance to probe the composition of the lunar interior. Its landing site is located on ejecta strips in Von Kármán crater that possibly originate from the neighboring Finsen crater. A surface rock and the lunar regolith at 10 sites along the rover Yutu-2 track were measured by the onboard Visible and Near-Infrared Imaging Spectrometer in the first three lunar days of mission operations. In situ spectra of the regolith have peak band positions at 1 and 2 μm, similar to the spectral data of Finsen ejecta from the Moon Mineralogy Mapper, which confirms that the regolith''s composition of the landing area is mostly similar to that of Finsen ejecta. The rock spectrum shows similar band peak positions, but stronger absorptions, suggesting relatively fresh exposure. The rock may consist of 38.1 ± 5.4% low-Ca pyroxene, 13.9 ± 5.1% olivine and 48.0 ± 3.1% plagioclase, referred to as olivine-norite. The plagioclase-abundant and olivine-poor modal composition of the rock is inconsistent with the origin of the mantle, but representative of the lunar lower crust. Alternatively, the rock crystallized from the impact-derived melt pool formed by the SPA-impact event via mixing the lunar crust and mantle materials. This scenario is consistent with fast-cooling thermal conditions of a shallow melt pool, indicated by the fine to medium-sized texture (<3 mm) of the rock and the SPA-impact melting model [Icarus 2012; 220: 730–43].     

大学何以要倡导和守护理想主义

大学的理想主义是大学对客观世界、社会生活以及大学自身寄予的美好期望所持有的观念体系,亦是大学对自身使命、责任、目标和操守所持有的一种既符合大学规律又有崇高要求的价值认定和信念追求,更是大学之为大学所必须固守、薪火相传并不受外界干扰的精神向往和文化灵魂。大学本身就是充满理想主义的人才培养和探求学问的场所,理想主义是大学不可或缺的对人具有深刻影响的文化精神,但不少大学已经呈现出与大学崇真、向善、求美之宗旨、之属性相悖的过度功利和势利。倡导和守护理想主义,其意义在于为大学的办学和发展及大学的教育者和被教育者提供一种美好的、纯洁的、积极的、向上的参照和追求。     

财务报告的历史演进和发展趋势

现代财务报告的发展经历了100多年的演进.早期,在"资产负债表"是唯一财务报表的情况下,会计报表主要用于揭示各资产和权益项目,而不是反映它们的现行价值.随着社会经济和技术的发展,出现了第二张主要财务报表"损益表".此后,又出现了第三张财务报表--"现金流量表".这样,早期的会计分类账演进成今天的包括资产负债表、利润表和现金流量表等报表的财务报告体系.从发展趋势看,发达国家已出现"第四张表",以报告全面损益;同时,还开始采用经营报告语言扩展系统(XBBL)在互联网上披露企业财务报告.     

新教育的历史使命:重建人文精神

近现代的中国由于受新旧价值观念和东西方文明的冲突,以及科学至上主义的影响,人文精神日渐失落,导致个体的人逐渐失去其成其为“人”的精神价值,社会也日益出现道德危机。中华民族迫切需要重建人文精神,人文教育的价值再次凸显。新时期的教育需要将人文精神的教育贯穿在整个教育理念中,树立生命教育观;要建设一支富有人文精神和人文素养的教师队伍,在教育实践中,实现教育目的、教育内容、教育方法和教育评价标准的人本性。新教育承担着重建人文精神的历史使命。     

人文精神视野下的大学使命

人文精神是一种历史的存在,在不同的时代有不同的内涵。当代大学的人文精神既包括对各种形态人文精神的包容,同时也要具备鲜明的时代特色。在今天的中国大学,人文教育被冷落直接导致了人文精神的流失。这固然有来自社会的消极影响,但是大学完全可以有更多的作为。对于大学而言,这是一种永不停息的精神诉求,其实这就是大学的使命。